1. Field of the Invention
The present invention relates to communication system for performing telephone communication or facsimile transmission by utilizing computer terminals such as personal computers and the like.
2. Description of the Related Art
For such a purpose, there has conventionally been available an apparatus, wherein a personal computer is directly connected to a subscriber's line by fitting a facsimile card or a modem card into the PCMCIA (Personal Computer Memory Card International Association) card slot of the computer.
This apparatus has only a single function system that a card must be prepared for every facsimile transmission or data communication and a PCMCIA card must be replaced by another in order to change a function. It also has a drawback that one computer may monopolize the subscriber's line.
There is another apparatus designed for the same purpose, wherein a plurality of computers are connected to a local area network (Intranet) and further connected to a public switched telephone network by a gate way having a facsimile function or a data communication function. These apparatus allow a plurality of terminals to individually make calls and seemingly share the subscriber's line, since these terminals are connected to the gate way. However, as a telephone number is not assigned to each computer, direct communication addressed to each computer from the public switched telephone network may not be performed and sharing of the subscriber's line is not provided in the true sense of the word. As in the case of the PCMCIA card, this gate way must be prepared for every function and thus this may also has only a single function system.
In such conventional communication system, it is necessary to install large-sized and complicated equipment in order to utilize various functions of the computer by the subscriber's line or an extension line. Therefore, it has been difficult to make sufficient use of various functions of the computer.